Data-centric integration modeling

ABSTRACT

The present disclosure describes methods, systems, and computer program products for data-centric integration modeling in an application integration system. One computer-implemented method includes receiving, by operation of an integration system, a logic integration program comprising a plurality of logic integration patterns that are defined in a data-centric logic integration language; generating a logical model graph based on the logic integration program, the logical model graph being runtime-independent; converting the logical model graph into a physical model graph, the physical model graph being runtime-specific; and generating logic integration runtime codes executable by the integration system based on the physical model graph.

CLAIM OF PRIORITY

This application claims priority under 35 USC § 120 to U.S. patentapplication Ser. No. 14/665,825, filed on Mar. 23, 2015, the entirecontents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure relates to application integration modeling in anintegration system, particularly for data-intensive applicationintegrations.

Application integration is a process of linking multiple businessapplications (e.g., supply chain management applications, enterpriseresource planning (ERP) systems, customer relationship management (CRM)applications, business intelligence applications, payroll and humanresources systems, etc.) together to simplify and automate businessprocesses. An integration system can include a number of logicintegration patterns (also referred to as integration logic orintegration logic programs) that form an integration process thatoperate on, for example, messages of applications. For example, messagescan be sent and received by integration adapters that provideapplications (e.g., business applications) with access to an integrationprocess.

Conventional modeling of message-based integration (e.g., businessapplication integration) scenarios is exclusively control-flow-centric,for example, by defining a control flow including a series of enterpriseintegration pattern (EIP) Icon Notations, although message-basedintegration is mainly about message routing and transformations that arebased on the data/content of a message. The conventional integrationmodeling underspecifies the data flow and can be deficient especiallyfor data-intensive application integrations.

SUMMARY

The disclosure generally describes computer-implemented methods,software, and systems for data-centric integration modeling. Onecomputer-implemented method includes receiving, by operation of anintegration system, a logic integration program comprising a pluralityof logic integration patterns that are defined in a data-centric logicintegration language; generating a logical model graph based on thelogic integration program, the logical model graph beingruntime-independent; converting the logical model graph into a physicalmodel graph, the physical model graph being runtime-specific; andgenerating logic integration runtime codes executable by the integrationsystem based on the physical model graph.

Other implementations of this aspect include corresponding computersystems, apparatus, and computer programs recorded on one or morecomputer storage devices, each configured to perform the actions of themethods. A system of one or more computers can be configured to performparticular operations or actions by virtue of having software, firmware,hardware, or a combination of software, firmware, or hardware installedon the system that in operation causes (or causes the system) to performthe actions. One or more computer programs can be configured to performparticular operations or actions by virtue of including instructionsthat, when executed by data processing apparatus, cause the apparatus toperform the actions.

The foregoing and other implementations can each optionally include oneor more of the following features, alone or in combination.

A first aspect, combinable with the general implementation, furthercomprising defining the logic integration program using the data-centriclogic integration language for declarative integration programming.

A second aspect, combinable with any of the previous aspects, whereindefining a logic integration program comprises: analyzing integrationlogic represented by the logical model graph; and adding integrationartifacts.

A third aspect, combinable with any of the previous aspects, wherein thelogical model graph comprises one or more annotations defined by thedata-centric logic integration language as one or more nodes of thelogical model graph.

A fourth aspect, combinable with any of the previous aspects, whereinthe logical model graph comprises no cycles.

A fifth third aspect, combinable with any of the previous aspects,wherein converting the logical model graph into the physical model graphcomprises: detecting patterns on the logical model graph; and performinga rule-based transformation of the patterns on the logical model graph;and mapping into implementation-specific messaging channels.

A sixth aspect, combinable with any of the previous aspects, furthercomprising optimizing the logical model graph.

The subject matter described in this specification can be implemented inparticular implementations so as to realize one or more of the followingadvantages. Example techniques for declarative, data-centric integrationscenario modeling are provided, which allows for automatic optimizationof scenarios by combining optimizations from both data management domainand integration control domain (e.g., data partitioning,parallelization, scatter/gather, splitter/gather). The example modelingis an integration domain-specific language (DSL) grounded ondata-centric languages and can be implemented in any relational logiclanguages, such as PROLOG, DATALOG, or XML- or JSON-based languages. Anannotation dialect for integration artifacts (e.g., sender/receiveradapter, aggregate, split) that cannot be automatically derived from thedata dependencies (e.g., Abstract Syntax Tree (AST)) can be added tointegration rules (e.g., DATALOG rules) to attach integration semantics.The example techniques can semantically extend integration programs andbuild an AST based on the actual pieces of data, data operations, and(integration-specific) annotations (e.g., as nodes) and theirinterdependencies (e.g., as edges). The techniques allow declarativelydescribing “what” shall be the result, instead the usual, imperative“how to get there”, thus making the approach more intuitive, loweringthe learning curve, and requiring less technical knowledge. The exampletechniques allow defining a rule-based (traversal) approach on the dataAST that derives basic integration patterns like messagetransformations, content-based routing, message filters, and inlinecontent enriching. The rule-based techniques allow specifyingmatch/execute conditions that are used to apply optimizations on thegraph, such as AST analysis (e.g., unnecessary operations), independentdata/operations (e.g., parallelization), and data partitioning. The(optimized) AST can be rewritten to a runtime-near message route graphusing graph transformation. The graph can be used to generateintegration runtime or intermediate code (e.g., DATALOG Blocksconstructs). Apart from some optimizations, the transformations can bebijective, thus allowing for runtime monitoring up to the originallanguage constructs (i.e., linking the actual runtime with theintegration syntax/user interface (UI)). When leveraging the runtimefeedback, this allows for debugging of integration constructs/programs.

The details of one or more implementations of the subject matter of thisspecification are set forth in the accompanying drawings and thedescription below. Other features, aspects, and advantages of thesubject matter will become apparent from the description, the drawings,and the claims.

DESCRIPTION OF DRAWINGS

FIG. 1A is a block diagram of an example environment for applicationintegration modeling according to an implementation.

FIG. 1B is a diagram of an example integration process flow according toan implementation.

FIG. 2 is a diagram of an example data-intensive application integrationscenario according to an implementation.

FIG. 3 is a listing of an example logical integration language (LiLa)program of the application integration scenario of FIG. 2 according toan implementation.

FIG. 4 is a diagram shows an example LiLa dependency graph (LDG) for theLiLa program of FIG. 3.

FIG. 5 is a diagram example route graph (RG) corresponding to the LDG ofFIG. 4 according to an implementation.

FIG. 6A is an example LDG of a join router pattern, and FIG. 6B is anexample RG 650 corresponding to the LDG of FIG. 6A according to animplementation.

FIG. 7A is an example LDG of a multicast pattern, and FIG. 7B is anexample RG corresponding to the LDG of FIG. 7A according to animplementation.

FIG. 8A is an example LDG of a remote enricher pattern, and FIG. 8B isan example RG corresponding to the LDG of FIG. 8A according to animplementation.

FIG. 9 is an example route graph in enterprise integration pattern(EIP)-icon notation corresponding to the LDG of FIG. 4 according to animplementation.

FIG. 10 is a listing of an example extended LiLa program 1000 of theapplication integration scenario of FIG. 2 according to animplementation.

FIG. 11 is an example extended LDG corresponding to the extended LiLaprogram of FIG. 10.

FIG. 12 is an example RG generated based on the LDG 1100 shown in FIG.11.

FIG. 13 is a flowchart of an example method for data-centric integrationmodeling according to an implementation.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following description is presented to enable any person skilled inthe art to make and use the disclosed subject matter, and is provided inthe context of one or more particular implementations. Variousmodifications to the disclosed implementations will be readily apparentto those skilled in the art, and the general principles defined hereinmay be applied to other implementations and applications withoutdeparting from scope of the disclosure. Thus, the present disclosure isnot intended to be limited to the described and/or illustratedimplementations, but is to be accorded the widest scope consistent withthe principles and features disclosed herein.

This disclosure generally describes computer-implemented methods,software, and systems for data-centric integration modeling in anapplication integration system. Particularly, a rule-based language forapplication integration, referred to as Logic Integration Language(LiLa), is provided, which defines integration logic tailored for moredata-intensive processing. With the more data-centric integrationlanguage and a relational logic-based implementation of integrationsemantics, example data-centric integration modeling techniques areprovided that allow for optimization from the data management domain(e.g., data partitioning, parallelization) to be combined with commonintegration processing (e.g., scatter/gather, splitter/gather). As such,the example data-centric integration modeling enables a more explicitdata flow (including, e.g., data formats/models, operations/processing)that can be specified and derived from the integration scenario models.The data flow can be more easily perceived and adapted, improvingclarity and flexibility of integration scenario description andfacilitating understanding and control of system's behaviors (e.g.,which data and how it is processed).

The example data-centric integration modeling techniques allow automatedoptimizations of the data flow and control flow, for example, by theintegration system, as an alternative or in addition to manualoptimizations, for example, by integration experts followingbest-practices guidelines, such as using scatter/gather pattern, whereapplicable. In some implementations, the example data-centricintegration modeling techniques can use the control flow as a constraintto design, adapt, optimize, or otherwise modify the data flow. In someimplementations, the example data-centric integration modelingtechniques can achieve optimal control-flow and data-flow modeling thatis not feasible by manual optimizations. The example data-centricintegration modeling techniques can allow resource-efficient processing(e.g., green/energy efficient processing) and improve systemperformances by optimizing the control-flow and data-flow, reducingredundancy, and enabling parallel processing.

FIG. 1A is a block diagram of an example environment 100 fordata-centric integration modeling. Specifically, the illustratedenvironment 100 can be an application integration system 100 thatincludes, or is communicably coupled with, plural client devices 102, aserver 104, and one or more external systems 106, connected using anetwork 108. For example, the environment 100 can be used to presentinformation on the plural client devices 102 using information availablefrom the server 104. Further, input can be received from users 109 onthe plural client devices 102 for analysis by the server 104.

At a high level, the server 104 comprises an electronic computing deviceoperable to collect, store, and provide access to information for use bythe client device 102. A data store of adapter information 110, forexample, can include information received from the plural client devices102. For example, users 109 can provide specific information for anadapter that the server 104 can use to characterize the adapter. Theadapter information 110 can also include information maintained by theserver 104 for use in characterizing adapters using information receivedfrom user inputs. The application server 112 can include a data store ofLiLa program information 111. For example, the LiLa program informationthat is stored can provide types, rules, syntax, semantics, and otherproperties of LiLa programs or patterns described below with referenceto FIGS. 2-13.

As used in the present disclosure, the term “computer” is intended toencompass any suitable processing device. For example, although FIG. 1Aillustrates a single server 104, the environment 100 can be implementedusing two or more servers 104, as well as computers other than servers,including a server pool. Indeed, the server 104 may be any computer orprocessing device such as, for example, a blade server, general-purposepersonal computer (PC), Macintosh, workstation, UNIX-based workstation,or any other suitable device. In other words, the present disclosurecontemplates computers other than general purpose computers, as well ascomputers without conventional operating systems. Further, illustratedserver 104 may be adapted to execute any operating system, includingLinux, UNIX, Windows, Mac OS®, Java™, Android™, iOS or any othersuitable operating system. According to some implementations, the server104 may also include, or be communicably coupled with, an e-mail server,a web server, a caching server, a streaming data server, and/or othersuitable server(s). In some implementations, components of the server104 may be distributed in different locations and coupled using thenetwork 108.

In some implementations, the server 104 includes an application server112 that performs processing at the server 104 that is needed to supportrequests for data and analysis of information received from the clientdevice 102. For example, the application server 112 can receiveadapter-related information and inputs from the client device 102.Further, the application server 112 can use the received information tocharacterize an adapter as having characteristics, as described belowwith reference to FIGS. 2-13.

The application server 112 includes a user request module 113, forexample, that can receive, from the client device 102, adapter-relatedinformation associated with an adapter. For example, the informationreceived can be information provided by the user in a client application114, such as a front end for inputting adapter-related information usedto characterize a specific adapter. The user request module 113 can alsoprepare data that is to be presented by a presentation module 118 at theclient device 102. For example, the user request module 113 can preparedata for presentation based on user inputs received by a communicationmodule 120. The inputs, for example, can include user inputs forspecifying particular information associated with an adapter. The userrequest module 113 can also be used by the server 104 for communicatingwith other systems in a distributed environment, connected to thenetwork 108 (e.g., the client device 102), as well as other systems (notillustrated) communicably coupled to the network 108. Generally, theuser request module 113 comprises logic encoded in software and/orhardware in a suitable combination and operable to communicate with thenetwork 108. More specifically, the user request module 113 may comprisesoftware supporting one or more communication protocols associated withcommunications such that the network 108 or interface's hardware isoperable to communicate physical signals within and outside of theillustrated environment 100.

The application server 112 further includes a communication patternmodule 115 for determining communication patterns associated with anadapter. For example, determining communication patterns can includeidentifying communication styles and bridges for a given adapter anddetermining one or more processing patterns, as described below withreference to FIGS. 2-13.

The application server 112 further includes a LiLa program module 119.For example, LiLa program module 119 can define, configure, optimize,convert, or otherwise manage a LiLa program according to exampletechniques described below with reference to FIGS. 2-13.

The application server 112 further includes a visualization module 122.As an example, the visualization module 122 can generate instructions sothat a visualization for a LiLa dependency graph (LDG) or a route graph(RG) can be displayed on the client device 102. For example, thevisualization can match one of the visualizations shown in FIGS. 2-13.

The server 104 further includes a processor 126 and memory 128. Althoughillustrated as the single processor 126 in FIG. 1A, two or moreprocessors 126 may be used according to particular needs, desires, orparticular implementations of the environment 100. Each processor 126may be a central processing unit (CPU), an application specificintegrated circuit (ASIC), a field-programmable gate array (FPGA), oranother suitable component. Generally, the processor 132 executesinstructions and manipulates data to perform the operations of theclient device 102. Specifically, the processor 126 executes thefunctionality required to receive and process requests from the clientdevice 102 and analyze information received from the client device 102.

The memory 128 (or multiple memories 128) may include any type of memoryor database module and may take the form of volatile and/or non-volatilememory including, without limitation, magnetic media, optical media,random access memory (RAM), read-only memory (ROM), removable media, orany other suitable local or remote memory component. The memory 128 maystore various objects or data, including caches, classes, frameworks,applications, backup data, business objects, jobs, web pages, web pagetemplates, database tables, repositories storing business and/or dynamicinformation, and any other appropriate information including anyparameters, variables, algorithms, instructions, rules, constraints, orreferences thereto associated with the purposes of the server 104. Insome implementations, memory 128 includes one or more of the adapterinformation 110 and the data store of LiLa program information 111.Other components within the memory 128 are possible.

Each client device 102 of the environment 100 may be any computingdevice operable to connect to, or communicate with, at least the server104 via the network 108 using a wireline or wireless connection. Ingeneral, the client device 102 comprises an electronic computer deviceoperable to receive, transmit, process, and store any appropriate dataassociated with the environment 100 of FIG. 1A.

A request handler 130, e.g., included in the application server 112, canreceive inputs and handle requests received from the client device 102.Specifically, the request handler 130 can receive user inputs, includingLiLa program information, entered by the user 109 on the clientapplication 114. In some implementations, the request handler 130 canalso process requests received from other sources in addition to clientdevices 102, e.g., requests received from external systems 106.

The illustrated client device 102 further includes a processor 132, amemory 134, and an interface 136. The interface 136 is used by theclient device 102 for communicating with other systems in a distributedenvironment—including within the environment 100—connected to thenetwork 108, e.g., the server 104, as well as other systems communicablycoupled to the network 108 (not illustrated). Generally, the interface136 comprises logic encoded in software and/or hardware in a suitablecombination and operable to communicate with the network 108. Morespecifically, the interface 136 may comprise software supporting one ormore communication protocols associated with communications such thatthe network 108 or interface's hardware is operable to communicatephysical signals within and outside of the illustrated environment 100.

Regardless of the particular implementation, “software” may includecomputer-readable instructions, firmware, wired and/or programmedhardware, or any combination thereof on a tangible medium (transitory ornon-transitory, as appropriate) operable when executed to perform atleast the processes and operations described herein. Indeed, eachsoftware component may be fully or partially written or described in anyappropriate computer language including C, C++, Java™, Visual Basic,assembler, Perl®, any suitable version of 4GL, as well as others. Whileportions of the software illustrated in FIG. 1A are shown as individualmodules that implement the various features and functionality throughvarious objects, methods, or other processes, the software may insteadinclude a number of sub-modules, third-party services, components,libraries, and such, as appropriate. Conversely, the features andfunctionality of various components can be combined into singlecomponents as appropriate.

As illustrated in FIG. 1A, the client device 102 includes the processor132. Although illustrated as the single processor 132 in FIG. 1A, two ormore processors 132 may be used according to particular needs, desires,or particular implementations of the environment 100. Each processor 132may be a central processing unit (CPU), an application specificintegrated circuit (ASIC), a field-programmable gate array (FPGA), oranother suitable component. Generally, the processor 132 executesinstructions and manipulates data to perform the operations of theclient device 102. Specifically, the processor 132 executes thefunctionality required to send requests to the server 104 and to receiveand process responses from the server 104.

The illustrated client device 102 also includes a memory 134, ormultiple memories 134. The memory 134 may include any memory or databasemodule and may take the form of volatile or non-volatile memoryincluding, without limitation, magnetic media, optical media, randomaccess memory (RAM), read-only memory (ROM), removable media, or anyother suitable local or remote memory component. The memory 134 maystore various objects or data, including caches, classes, frameworks,applications, backup data, business objects, jobs, web pages, web pagetemplates, database tables, repositories storing business and/or dynamicinformation, and any other appropriate information including anyparameters, variables, algorithms, instructions, rules, constraints, orreferences thereto associated with the purposes of the client device102.

The illustrated client device 102 is intended to encompass any computingdevice such as a smart phone, tablet computing device, PDA, desktopcomputer, laptop/notebook computer, wireless data port, one or moreprocessors within these devices, or any other suitable processingdevice. For example, the client device 102 may comprise a computer thatincludes an input device, such as a keypad, touch screen, or otherdevice that can accept user information, and an output device thatconveys information associated with the operation of the server 104 orthe client device 102 itself, including digital data, visualinformation, or a graphical user interface (GUI) 140, as shown withrespect to and included by the client device 102. The GUI 140 interfaceswith at least a portion of the environment 100 for any suitable purpose,including generating user interface screens that support user input ofadapter-related information and display visualizations of adapters usinginformation received from the server 104.

FIG. 1B is a diagram of an example integration process flow 150. In someimplementations, the integration process flow 150 includes an adapterprocess flow and can involve operations associated with a LiLa compilertoolchain 152, adapters 154 and 156, and an integration process 158.Processing among the adapters 154 and 156, and an integration process158 can include information sent by an application system 170 (e.g., asender), a sender-side adapter 172, a receiver-side adapter 174, and areceiver application system 178. Other processing is possible. Theprocessing can make use of information stores in data stores 180 used bythe adapters.

In some implementations, the LiLa compiler toolchain 152 includesvarious steps for compiling LiLa programs into programs or routesexecutable by the integration system runtime 182. For example, if APACHECAMEL is used as the integration system runtime 182, the LiLa programscan be complied into message channels in APACHE CAMEL, namely, CAMELRoutes, based on the example rule-based, graph transformation toolchainor method flow 152.

For example, a step 161 can parse LiLa programs. At step 162, forexample, the parsed and identified LiLa programs are translated into alogical model graph, such as LiLa dependency graph (LDG), for example,according to example techniques described below with respect to FIG. 4.A step 163 can perform rule- and cost-based optimizations on the logicalmodel graph, for example, to remove redundancy or cycles in the logicalmodel graph. At step 164, a rule-based pattern detection can beperformed to identify patterns in the logical model graph and re-writethe logical model graph into a physical runtime model graph. Forexample, the LDG can be bi-directionally transformed to a generalmessage channel (or route) graph, according to example techniquesdescribed below with respect to FIG. 5. A step 165, for example, cangenerate runtime code (e.g., CAMEL routes in APACHE CAMEL runtimesystem) based on the physical runtime model graph. A step 166, forexample, can package and deploy the generated runtime code. The LiLacompiler toolchain 152 can use LiLa program information in a LiLaregistry 160, e.g., that includes information associated withdefinitions and characteristics of different LiLa program types. TheLiLa compiler toolchain 152 includes processing, for example, thatsupports steps in the method process described below with respect toFIG. 13.

Integration semantics can be described based on a comprehensive (oftengraphically depicted) syntax and execution semantics (e.g., processmodel). Some implementations can collect a widely used and acceptedcollection of integration patterns that are typical concepts used whenimplementing a messaging system and have proven to be useful inpractice. However, the implementations may not specify a semantic modelfor the formalization of the integration syntax and semantics. Mostnoticeable, the integration adapter modeling with its manifoldcharacteristics can be reduced to a channel adapter icon in the figure.

In some implementations, a domain-specific language (DSL) can be studiedand provided with well-defined building blocks for modeling enterpriseintegration patterns (EIPs) in the Business Process Model and Notation(BPMN), which is typically considered a “de-facto” standard for modelingbusiness process semantics and their runtime behavior. EIPs can bemapped to BPMN-compatible syntax and defined execution semantics adaptedto message processing. The use of EIPs can be extended to end-to-endflows of messages, called integration flows (IFlows). An IFlow can beconsidered as message-based integration from a sending application(e.g., sender, BPMN participant) to one or many receiving applications(e.g., receiver(s), BPMN participants). The message-based integrationcan use BPMN message flow configurations (e.g., denoting the inbound andoutbound adapters) and dedicated participant(s) that specify anintegration process (composition of EIPs). In some implementations, BPMNcan be used for defining a “message-based integration” DSL due to itssufficient coverage of control flow, data/exception flow, processmodeling capabilities, and execution semantics. Current work in the areaof data in business processes, for example, includes configuration-basedrelease processes (COREPRO), which mainly deals with data-driven processmodeling, (business) object status management, and UML activitydiagrams. However, BPMN can achieve higher coverage in the categoriesrelevant for the approach. As will be appreciated by those of ordinaryskill in the art, other design artifacts and modeling methodologiesinstead of or in addition to EIPs and BPMN can be used.

FIG. 2 is a diagram of an example data-intensive application integrationscenario 200 according to an implementation. Specifically, thedata-intensive application integration scenario 200 includes a “SoccerPlayer Event” integration scenario from sports management in the EIPicon notation. Additional or different integration scenarios arepossible.

In an example, FIG. 2 shows that player event data is gained through aFile/Polling Consumer 210, loading game events 211 collected by sensorsattached to the players and the playing field during a soccer match.Depending on the event code, a Content-based Router pattern 230 is usedto route the messages to specific filter operations for “Shots on goal”and “Player at ball” through Content Filters 232 and 234, respectively.Additional player information 241 and 243 can be merged into theresulting messages using Content Enrichers 242 and 244 for “Shots ongoal” and “Player at ball,” respectively. Then, the messages areconverted into the formats understood by their receivers using MessageTranslators 252 and 254 accordingly. The “Shots on goal” information canbe posted as twitter feed, represented by a Twitter endpoint 262, andball possession information can be stored to file, represented by a fileendpoint 264.

The multiple integration patterns (e.g., the File/Polling Consumer 210,Content-based Router pattern 230, Content Filters 232 and 234, ContentEnrichers 242 and 244, Message Translators 252 and 254) model a controlflow. The message formats (e.g., “Game events” 211, “Player information”241 and 243) and the actual data processing (e.g., routing and filterconditions, enricher and mapping programs) remain hidden on a secondlevel configuration.

In some implementations, a more data-aware formalization is desirablethat treats data as a first-level configuration of an integrationscenario. Such a data-centric presentation can give an integrationexpert immediate control over the core aspect of integration, the data,and its format. The data-centric presentation can reduce or eliminatethe burden of explicitly modeling the system's control flow and allowautomatic configuration and optimization by the system itself, whilekeeping the options of manual best practices and optimizations.

Logic Integration Language (LiLa) provides an example data-centricmodeling approach and formalization tailored to data-intensive,message-based integration. In some implementations, DATALOG can be usedto re-define core EIPs as part of a conventional integration system.DATALOG allows for data processing closer to its storage representation,and can be sufficiently expressive for the evaluation of EIPs. LiLaprograms can be based on standard DATALOG+. Example integration-specificextensions can be defined.

FIG. 3 is a listing 300 of an example LiLa program of the soccer gameevent integration scenario of FIG. 2 according to an implementation. Inthis example, data flow, formats, and operations are represented asDATALOG program with annotations. Listing 300 shows a file-based messageadapter @from 310 that reads a stream of game events in the JSON format,canonically converts and projects the message body to DATALOG facts ofthe form gE. Several DATALOG rules represent operations on the data-likefilters (e.g., predicates g 320, p 330), enricher @enrich 360, thatloads and merges pInfo from gByP 340 and pByB 350), before binding theintentional database (IDB) (i.e., relation defined by one or more rules)relations to receiver endpoints @to 370 and 380 that only pass specifiedpredicates and (canonically) convert them to the configured format(e.g., JSON).

In some implementations, based on the LiLa programs (e.g., the exampleLiLa program 300), integration semantics and an efficient control flowcan be derived using pattern detection. In some implementations, LiLaprograms can be synthesized and implemented in integration systemruntimes, for example, the open-source integration system APACHE CAMELthat implements most of the integration semantics in the form of EIPs.In some instances, the usage of a more data-centric message processingis especially promising, for example, for message transformations, whilethe routing efficiency remains similar to the conventional processing,and from an end-to-end messaging point of view. Furthermore, thedata-centric modeling with LiLa leverages the potential foroptimizations and better modeling clarity compared to the existingcontrol flow-centric languages.

The Enterprise Integration Patterns (EIPs) define operations on theheader (i.e., payload's meta-data) and body (i.e., message payload) of amessage, which are normally implemented in the integration system hostlanguage (e.g., JAVA, C#). Therefore, the actual integration operation(e.g., the content developed by an integration expert like mappingprograms and routing conditions) can be differentiated from theimplementation of the runtime system that evaluates the contentoperations and processes their results. In some implementations, thecontent operations can be refined using DATALOG, leaving the runtimesystem (implementation) as is. The resulting set of operations andintegration language additions, which can be referred to as IntegrationLogic Programming (ILP), targets an enhancement of conventionalintegration systems for data-intensive processing, while preserving thegeneral integration semantics like Quality of Service (e.g., besteffort, exactly once) and the Message Exchange Pattern (e.g., one-way,two-way). In other words, the content part for the patterns can beevaluated by a DATALOG system, which is invoked by an integration systemthat processes the results.

Canonical Data Model

In some implementations, for example, when connecting applications,various operations are executed on the transferred messages in a uniformway. The arriving messages are converted into an internal formatunderstood by the pattern implementation, called Canonical Data Model(CDM), before the messages are transformed to the target format. Hence,if a new application is added to the integration solution, onlyconversions between the CDM and the application format have to becreated. Consequently, for the re-definition of integration patterns, wedefine a CDM as DATALOG Program, which consists of a set of facts, withan optional set of (supporting) rules as message body and a set ofmeta-facts that describes the actual data as header. The meta-factsencode the name of the fact's predicate and all parameter names withinthe relation as well as the position of each parameter. With thatinformation, parameters can be accessed by name instead of position byDATALOG rules (e.g., for selections, projections).

Relational Logic Integration Patterns

Some example DATALOG operations include join, projection, union, andselection. The join of two relations r(x,y) and s(y,z) on parameter y isencoded as j(x,y,z)←r(x,y),s(y,z), which projects all three parametersto the resulting predicate j. More explicitly, a projection on parameterx of relation r(x,y) is encoded as p(x)←r(x,y). The union of r(x,y) ands(x,y) is u(x,y)←r(x,y). u(x,y)←s(x,y), which combines several relationsto one. The selection r(x,y) according to a built-in predicateφ(x,[const|z]) is encoded as s(x,y)←r(x,y),φ(x,[const|z]), which onlyreturns s(x,y) records for which φ(x,[const|z]) evaluates to true for agiven constant value const or a variable value z. Built-in predicatescan be numerical, binary relations φ(x,const) like <,>,<=,>=,= as wellas string, binary relations like equals, contains, startswith, endswith,numerical expressions based on binary operators like =,+,−,*,/(e.g.,x=p(y)+1) and operations on relations like y=max(p(x)),y=min(p(x)),which would assign the maximal or the minimal value of a predicate p toa parameter y.

In some implementations, the example techniques allow each singlepattern definition to evaluate arbitrary DATALOG rules, queries, andbuilt-in predicates. In some implementations, the example techniquesallow the DATALOG to perform pattern mapping to identify and focus onthe most relevant DATALOG operations for a specific pattern.

Message Routing Patterns.

The routing patterns can be seen as control and data flow definitions ofan integration channel pipeline. The routing patterns can access themessage to route it within the integration system and eventually to itsreceiver(s), and can influence the channel and message cardinality aswell as the content of the message. The most common routing pattern thatdetermines the message's route based on its body is the Content-basedRouter. The stateless router has a channel cardinality of 1:n, where nis the number of leaving channels, while one channel enters the router,and a message cardinality of 1:1. The entering message constitutes theleaving message according to the evaluation of a routing condition. Thiscondition is a function rc, with {out₁, out₂, . . . ,out_(n)}=rc(msg_(in).body.x,conds), where msg_(in) determines theentering message and body.x is an arbitrary field x of its structure.The function rc evaluates to a list of Boolean output on a list ofconditions conds for each leaving channel. The output {out₁, out₂, . . ., out_(n)} is a set of Boolean values for each of the n ∈ N leavingchannels.

In some instances, only one channel must be evaluated to true, allothers to false. The Boolean output determines on which leaving channelthe message is routed further (i.e., exactly one channel will route themessage). Common integration systems implement a routing function thatprovides the entering message msg_(in), represented by a DATALOG program(e.g., mostly facts) and the conds configurations as DATALOG rules.Since standard DATALOG rules cannot directly produce a Boolean result,there are at least two ways of re-defining rc: (a) by a supportingfunction in the integration system, or (b) by adding Boolean DATALOGfacts for each leaving channel that are joined with the evaluatedconditions and exclusively returned by projection (not furtherdiscussed). An additional function help rc for option (a) could bedefined as {out₁, out₂, . . . , out_(n)}=help rc(list(list(fact))),fitting to the input of the routing function, where list(list(fact))describes the resulting facts of the evaluation of conds for eachchannel. The function help rc emits true, if and only if list(facts)6=Ø, and false otherwise. In some implementations, the ILP routingcondition is defined as list(fact)=ilp_(rc)(msg_(in).body.x,conds),while being evaluated for each channel condition, thus generatinglist(list(fact)). The conds would then mainly be DATALOG operations likeselection or built-in predicates. For the message filter, which is aspecial case of the router that distinguishes only in its channelcardinality of 1:1 and the resulting message cardinality of 1:[0|1], theilp_(rc) would have to be evaluated once.

By contrast, the stateless Multicast and Recipient List patterns routemultiple messages to leaving channels, which gives them a message andchannel cardinality of 1:n. While the multicast routes messagesstatically to the leaving channels, the recipient list determines thereceiving channels dynamically. The receiver determination function rd,with {out₁, out₂, . . . , out_(n)}=rd(msg_(in).[header.y|body.x]).,computes n ∈ N receiver channel configurations {out₁, out₂, . . . ,out_(n)} by extracting their key values either from an arbitrary messageheader field y or from the body x field of the message. In someimplementations, the integration system has to implement a receiverdetermination function that takes the list of key-strings {out₁, out₂, .. . , out_(n)} as input, for which it looks up receiver configurationsrecv_(i), recv_(i+1), . . . , recv_(i+m), where i,m,n ∈ N and m≤n, andpasses copies of the entering message {msg′_(out), msg″_(out), . . . ,msg_(out) ^(m′)}. In terms of DATALOG, rd_(ilp) is a projection fromvalues of the message body or header to a unary, output relation. Forinstance, the receiver configuration keys recv₁ and recv₂ can be part ofthe message body like body(x′, recv′₁), body(x′, recv′₂). and rd_(ilp)would evaluate a DATALOG rule similar to config(y)←body(x,y). For moredynamic receiver determinations, a dynamic routing pattern could beused. The example ILP definitions allow deviations from the originalpattern and can extend the expressiveness of the recipient list. In someimplementations, the multicast and join router patterns are staticallyconfigurable 1:n and n:1 channel patterns, which do not need are-definition as ILP.

The antipodal Splitter and Aggregator patterns both have a channelcardinality of 1:1 and create new leaving messages. Therefore, thesplitter breaks the entering message into multiple (smaller) messages(e.g., message cardinality of 1:n) and the aggregator combines multipleentering messages to one leaving message (e.g., message cardinality ofn:1). To be able to receive multiple messages from different channels, aJoin Router pattern with a channel cardinality of n:1 and messagecardinality of 1:1 can be used as a predecessor to the aggregator. Thus,the stateless splitter uses a split condition sc, with {out1, out2, . .. , outn}&=sc(msg_(in).body,conds), which accesses the enteringmessage's body to determine a list of distinct body parts {out₁, out₂, .. . , out_(n)}, based on a list of conditions conds, that are eachinserted to a list of individual, newly created leaving messages{msg_(out1), msg_(out2), . . . , msg_(outn)} with n ∈ N by a splitterfunction. The header and attachments are copied from the entering toeach leaving message. The re-definition sc_(ilp) of split condition scevaluates a set of DATALOG rules as conds, which mostly use DATALOGselection and sometimes built-in and join constructs (the latter two aremarked “light blue”). Each part of the body out_(i) is a set of factsthat is passed to a split function, which wraps each set into a singlemessage.

The stateful aggregator defines a correlation condition, completioncondition and an aggregation strategy. The correlation condition crc,with coll_(i)=crc(msg_(in).[header.y|body.x], conds), determines theaggregate collection coll_(i), with i ∈ N, based on a set of conditionsconds to which the message is stored. The completion condition cpc, withcpout=cpc(msg_(in).[header.y|body.x]), evaluates to a Boolean outputcpout based on header or body field information (similar to the messagefilter). If cpout==true, then the aggregation strategy as, withaggout=as(msg_(in1), msg_(in2), . . . , msg_(inn)), is called by animplementation of the messaging system and executed; otherwise, thecurrent message is added to the collection coll_(i). The as evaluatesthe correlated entering message collection coll_(i) and emits a newleaving message msg_(out). For that, the messaging system has toimplement an aggregation function that takes aggout (i.e., the output ofas) as input. These three functions are re-defined as crc_(ilp),cpc_(ilp) such that the conds are rules mainly with selection andbuilt-in DATALOG constructs. The cpc_(ilp) makes use of the defined helprc function to map its evaluation result (i.e., list of facts or empty)to the Boolean value cpout. The aggregation strategy as is re-defined asas_(ilp), which mainly uses DATALOG union to combine lists of facts fromdifferent messages. The message format remains the same. To transformthe aggregates' formats, a message translator should be used to keep thepatterns modular. However, the combination of the aggregation strategywith translation capabilities could lead to runtime optimizations.

Message Transformation Patterns

In some implementations, the transformation patterns exclusively targetthe content of the messages in terms of format conversations andmodifications.

The stateless Message Translator changes the structure or format of theentering message without generating a new one (i.e., channel, messagecardinality 1:1). For that, the translator computes the transformedstructure by evaluating a mapping program mt, withmsg_(out).body=mt(msg_(in).body). Thus, the field content can bealtered.

The related Content Filter and Content Enricher patterns can be subsumedby the general Content Modifier pattern and share the samecharacteristics as the translator pattern. The filter evaluates a filterfunction mt, which only filters out parts of the message structure,e.g., fields or values, and the enricher adds new fields or values asdata to the existing content structure using an enricher program ep,with msg_(out).body=ep(msg_(m).body,data).

The re-definition of the transformation function mt_(ilp) for themessage translator can use DATALOG join and projection (plus built-insfor numerical calculations and string operations, thus marked “lightblue”) and DATALOG selection, projection, and built-in (mainly numericalexpressions and character operations) for the content filter. Whileprojections allow for rather static, structural filtering, the built-inand selection operators can be used to filter more dynamically based onthe content. The resulting DATALOG programs are passed asmsg_(out).body. In addition, the re-defined enricher program ep_(ilp)can use DATALOG union operations to add additional data to the messageas DATALOG programs.

Pattern Composition

The defined patterns can be composed to more complex integrationprograms (e.g., integration scenarios or pipelines). From the manycombinations of patterns, two example structural patterns that arefrequently used in integration scenarios are described below: (1)scatter/gather and (2) splitter/gather [12]. Both patterns can besupported by the patterns re-defined as ILPs.

The scatter/gather pattern (with a 1:n:1 channel cardinality) is amulticast or recipient list that copies messages to several staticallyor dynamically determined pipeline configurations, which each evaluate asequence of patterns on the messages in parallel. Through a join routerand an aggregator pattern, the messages are structurally andcontent-wise joined.

The splitter/gather pattern (with a 1:n:1 message cardinality) splitsone message into multiple parts, which can be processed in parallel by asequence of patterns. In contrast to the scatter/gather, the patternsequence is the same for each instance. A subsequently configuredaggregator combines the messages to one.

Logic Integration Language

In the context of data-intensive message-processing, conventionalcontrol flow-centric integration languages do not allow to design thedata flow. Through the re-definition of the integration patterns withDATALOG as ILPs, a foundation for a data-centric definition ofintegration scenarios is provided. In some implementations, the languagedesign of the subsequently defined Logic Integration Language (LiLa) isbased on DATALOG, which specifies programs that carefully extendstandard DATALOG+ by integration semantics using annotations for messageendpoints and complex routing patterns. Additional or differentrelational logic languages can be used.

Table 1 shows an example format of an annotation in LiLa. The annotationincludes a head with name preceded by “@” and zero or more parametersenclosed in brackets, as well as a body enclosed in curly brackets.Variations of the format can be contemplated.

TABLE 1 Format of an annotation in LiLa @<annotationName>(<parameter>⁺){ <Annotation Body> }

Logic Integration Language Programs

In some implementations, a LiLa program defines dependencies betweenDATALOG facts, rules, and annotations that are similar to the dependencygraph of a DATALOG program (“DG_(D)”). A cyclic dependency graph DG_(D)of a (recursive) DATALOG program can be defined as DG_(D)=(V_(D),E_(D)),where the nodes V_(D) of the graph are IDB predicates, and the edgesE_(D) are defined from a node n₁ ∈ N (predicate 1) to a node n₂ ∈ N(predicate 2), if and only if, there is a rule with predicate 1 in thehead and predicate 2 in the body.

In some implementations, the directed, acyclic LiLa dependency graph(“LDG”) can be defined as LDG=(V_(p),E_(p)), where V_(p) are collectionsof IDB predicates (also be referred to as processors). An edge E_(p)from processor p₁ ∈ V_(p) to p₂ ∈ V_(p) exists, if there is a rule withpredicate 1 from p₁ in the head and predicate 2 from p₂ in the body.Hence, the LDG contains processors with embedded cyclic rule dependencygraphs, which do not lead to cycles in the LDG. In contrast to theDG_(D), annotations are added to the LDG as nodes. If an annotation usesa predicate, an edge from that predicate is drawn to the node of theannotation (i.e., annotation depends on that predicate). If anotherannotation or rule uses the predicates produced by an annotation, anedge from the annotation to the node representing the annotation orrule, which uses the data produced by the annotation, is drawn.

FIG. 4 is a diagram showing an example LiLa dependency graph (“LDG”) 400for the LiLa program depicted in Listing 300 of FIG. 3. For example,according to Listing 300, because the annotation or rule gByP 340 usesthe predicates produced by annotations g 320 and pInfo 360, in the LDG400, edges 431 and 433 from the annotations g 432 and pInfo 435 to thenode gByP 442 are drawn, respectively, representing that the annotationgByP 442 uses the data produced by the annotations g 432 and pInfo 435.The message endpoint nodes 452 and 454 are labeled with theirconsumer/producer URI with the predicate name of the rule for contentfilters.

Endpoint-Specific Extensions

To connect the message sender, the Fact Source, with the messagereceiver, the Routing Goal, LiLa extends DATALOG by @from, @toannotation statements similar to the open source integration systemAPACHE CAMEL Nodes of LDG with no incoming edges are either extentionaldatabase (EDB) (e.g., relation stored in data or knowledge base)predicates or fact sources. Nodes with no outgoing edges are (mostly)routing goals. The only counter example are obsolete/unused processingsteps, which can be deleted in some implementations.

Table 2 shows an example definition of a fact source in LiLa. In someimplementations, the sender-facing fact source specifies the sender'stransport and message protocol. The fact source definition in Table 2includes a location configuration URI that can be directly interpretedby an integration system and defines the location of the facts andformats the message format of the data source (e.g., JSON, CSV, XML).The annotation body specifies the format's relations in the form ofDATALOG facts. The message format can be canonically converted toDATALOG programs according to the ILP-CDM.

TABLE 2 Example definition of a fact source in LiLa@from(<location>,<format>) { <relationName(<parameter>⁺)>.⁺ }

Table 3 shows an example definition of a routing goal in LiLa. In someimplementations, the routing goal definitions can specify thereceiver-facing transport and message protocols. Therefore, the ILP-CDMcan be canonically converted to the message format understood by thereceiver.

TABLE 3 Example definition of a routing goal in LiLa@to(<producerURI>,<format>) { <relationName>[<linebreak><relationName>]*}

Inherent Integration Patterns

The DATALOG facts provided by the fact source can be directly evaluatedby DATALOG rules. The LiLa dependency graph can be used to automaticallyidentify, for example, message transformation and basic routingpatterns.

Message Transformation Patterns.

Example message transformation patterns that can be derived from the LDGinclude Content Filter, Message Translator, and the local ContentEnricher.

The content filter and message translator patterns are used to filterparts of a message as well as to translate the message's structure. Bothcan be inherently declared in LiLa by using DATALOG rules, which arecollected in processors of the LDG. Each set of rules producing the samepredicate corresponds to a filter or translator in the integrationmiddleware. For instance, the LiLa program 300 in FIG. 3 for the soccerexample produces two content filters: one for the relation gByP andanother one for the relation pByB. The routing between multiple contentfilters is decided based on the dependency graph of the LiLa program. Ifa node has a single outgoing edge, the incoming data is directly routedto the processor corresponding to the subsequent node. If a node hasmultiple incoming edges, a join router pattern can be present, which isdetected and transformed as described with reference to FIGS. 6A and 6B.The same is the case for a node having multiple outgoing edges, whichcorresponds to a multicast pattern.

For the local content enricher, LiLa allows specifying facts in a LiLaprogram. The facts can be treated as a processor (e.g., a node in LDG)and can be automatically placed into the message after a relation withthis name is produced.

Message Routing Patterns

In addition to the message transformation patterns, some routingpatterns can be derived from the dependency graph such as, for example,Multicast, Message Filter, Content-based Router, and Join Router.

The multicast pattern can be used as part of the common map/reduce-stylemessage processing. The multicast is derived by analyzing the dependencygraph for independent rules to which copies of the message are provided.

The message filter removes messages according to a filter condition. Insome implementations, a special construct is not necessary for themessage filter. For example, filtering of a message can be achieved byperforming a content filtering, which leads to an empty message. Emptymessages are discarded before sending the message for further processingto a routing goal. This behavior can be used to describe a content-basedrouter, which distinguishes from the filter by its message cardinalityof 1:n. However in LiLa, the router can be used with a channelcardinality of 1:n (i.e., multicast) with message filters on eachleaving message channel.

The join router can be a structural channel combining pattern. The joinrouter has a channel cardinality of n:1. The join router only combineschannels, not messages. For that, an aggregator is used that is definedsubsequently.

Routing-Specific Extensions

In some implementations, the more complex routing patterns Aggregator,Splitter, and remote Content Enricher can neither be described bystandard DATALOG nor inherently detected in the dependency graph.Special annotations for these patterns can be defined.

Table 4 shows an example definition of an aggregator in LiLa accordingto an implementation. The @aggregate annotation is associated withpre-defined aggregation strategies like union and either time-(e.g.,completionTime=3) or number-of-messages-based completion condition(e.g., completionSize=5). The annotation body includes several DATALOGqueries. The message correlation can be based on the query evaluation,where true means that the evaluation result is not an empty set of factsand false otherwise. As the aggregator does not produce facts with a newrelation name, but combines multiple messages keeping their relations,it is challenging how to reference to the aggregated relations in a LiLaprogram as their name does not change (i.e., message producing). In someinstances, when building the dependency graph, it is undecidable whethera rule uses the relation prior or after aggregation. In someimplementations, to prevent the user specifying explicitly whether he orshe means the relation prior or after aggregation in every rule using apredicate used in an aggregator, some or all predicates can be suffixedafter an aggregation step with -aggregate by default. In combinationwith a join router, messages from several entering channels can becombined.

TABLE 4 Definition of an aggregator in LiLa@aggregate(<aggregationStrategy>,< completionCondition>) {<?-<relationName>(<parameter>⁺).>⁺ }

Table 5 shows an example definition of a splitter in LiLa according toan implementation. LiLa specifies the splitter as in Table 5 with a new@split annotation, which does not have any parameters in the annotationhead. DATALOG queries can be used in the annotation body as splitterexpressions. The queries are evaluated on the exchange, and eachevaluation result is passed for further processing as a single message.In some implementations, similar to the aggregator, all newly generatedrelations leaving a splitter are suffixed with -split by default inorder to not have to explicitly specify whether the relation prior orafter splitting is meant.

TABLE 5 Definition of a splitter in LiLa @split( ){<?-<relationName>(<parameter>⁺).>⁺ }

Table 6 shows an example definition of a remote content enricher in LiLaaccording to an implementation. The remote content enricher can be seenas a special message endpoint. In some implementations, for an enricherincluding data from a file, the filename and format can be specified asshown in Table 6. Similar to the fact source, a set of relations has tobe specified. Again, a canonical conversion from the specified fileformat to the ILP-CDM can be conducted according to the exampletechniques described above. If the relations to enrich via thisconstruct are already generated by another construct or DATALOG rule,they are enriched after this construct by adding the additional facts tothe message. If there is no construct or DATALOG rule producing therelations specified in the annotation body, the relations are enricheddirectly before their usage. The enricher construct is especially usefulwhen a single message shall be combined with additional information.

TABLE 6 Definition of a remote content enricher in LiLa@enrich(<filename>,<format>) { <relationName(<parameter>⁺).>⁺ }

Synthesis of Logic Integration Language Programs

The defined LiLa constructs can be combined into complex representationsof integration programs that can be executed by integration systems(e.g., open-source integration system APACHE CAMEL). For instance, ifAPACHE CAMEL is used as the integration system, the LiLa programs can becompiled into message channels in APACHE CAMEL, namely, CAMEL Routes. Insome implementations, to guarantee data-intensive processing, LiLaprograms are not synthesized to APACHE CAMEL constructs directly, but tothe ILP integration pattern re-definitions that are integrated into therespective system implementations. The example rule-based, graphtransformation LiLa compiler toolchain 152 of FIG. 1B can be used tosynthesize and compile LiLa programs into executable integrationprograms by integration systems.

Message Channel/Route Graph

In some implementations, a platform-independent message channelrepresentation, referred to as Route Graph (RG), enables a graphtransformation t: LDG→RG and an efficient code generation for differentruntime systems. The transformation can include a two-step process: Inthe first step, a condition is evaluated on each edge or node of theLDG, respectively. If the condition evaluates to true, furtherprocessing on this node/edge is performed. The second step is theexecution of the actual transformation.

The route graph RG can be defined as RG=(V_(R),E_(R)), where the nodesV_(R) are runtime components of an integration system (representing anILP-EIP), and the edges E_(R) are communication channels from one noden₁ ∈ V_(R) to another node n₂ ∈ V_(R), or itself n₁. The nodes in V_(R)can be partitioned to different routes, while edges in E_(R) from oneroute to another have to be of type to for the source node and of typefrom for the target node.

FIG. 5 is an example route graph (RG) 500 corresponding to the LDG 400of FIG. 4 for the example soccer player event scenario described in FIG.2 according to an implementation. The message flow (e.g., edges 531 and533) between separately generated routes (denoted by dashed lines)indicate a to/from construct. Consequently, the LiLa program 300 fromFIG. 3 results in four distinct routes, e.g., with a multicastmulticast(direct:p,direct:g) 530 and a file-enricher from(direct:enrichpinfo) 544 identified through pattern detection.

Pattern Detection and Transformation

The more complex, structural join router, multicast, and remote enricherpatterns can be automatically derived from the LDG 400 through arule-based pattern detection approach. With these building blocks,optimizations in integration systems, such as the map/reduce-likescatter/gather pattern, which is a combination of the multicast, joinrouter, and aggregator patterns, can be synthesized. The rule-baseddetection and transformation approach defines a matching function[true|false]=mf_(LDG,mc) on LDG, with matching condition mc and atransformation t_(G), with t_(G): LDG→RG. The matching function denotesa node and edge graph traversal on the LDG that evaluates to true if thecondition holds, false otherwise. The transformation t_(G) is executedonly if the condition holds.

Join Router

FIG. 6A is an example LDG 600 of a join router pattern and FIG. 6B is anexample RG 650 corresponding to the LDG 600 of FIG. 6A after patterndetection and transformation according to an implementation. The routeris a m:1 message channel join pattern, which usually has to be combinedwith an aggregator to join messages. The match condition is defined asMC_(JR)=deg⁻(n_(i))>1, where deg⁻(n_(i)) determines the number ofentering message channels on a specific node n_(i) ∈ V_(P), with i ∈ N.Hence, only in the case of multiple entering edges, the graphtransformation t_(jr) is executed. The transformations t_(jr1—3) changethe RG: t_(jr1):n_(i)→n_(fd)⊕n_(i). For all matching nodes n_(i), afrom-direct node n_(fd) is added, denoted by ⊕. Additionally, all nodesn_(j) with direct, outgoing edges to the matching node get an additionalto-direct node n_(td): n_(jr2):n_(j)→n_(j)⊕n_(td). Then, all originaledges em have to be removed: t_(jr3):E_(P)→E_(P)\e_(m).

Multicast

FIG. 7A is an example LDG 700 of a multicast pattern and FIG. 7B is anexample RG 750 corresponding to the LDG 700 of FIG. 7A after patterndetection and transformation according to an implementation. Themulticast has a channel cardinality of 1:n. The match condition isdefined as mc_(Mu)=deg⁺(n_(i))>1, where deg⁻(n_(i)) determines thenumber of leaving message channels on a specific node n_(i) ∈ V_(P),with i ∈ N. Hence, only in case of multiple leaving edges, the graphtransformation t_(jr) is executed. The transformations t_(mu1—3) changethe RG: t_(mu1):n_(i)→n_(i)⊕n_(multic{nj)}. For all matching nodesn_(i), a multicast node n_(multic) is added, which references allprevious neighboring nodes n_(j) via leaving edges. Then, a from-directnode n_(fd) is added to all neighboring nodes n_(j) throughtransformation t_(mu2):n_(j)→n_(fd)⊕n_(j). Additionally, all originaledges e_(m) have to be removed: t_(mu3):E_(P)→E_(P)\e_(m).

Remote Enricher.

FIG. 8A is an example LDG 800 of a remote enricher pattern and FIG. 8Bis an example RG 850 corresponding to the LDG 800 of FIG. 8A afterpattern detection and transformation according to an implementation. Anenricher potentially merges several predicate relations to the mainroute as additional data. Therefore, it has to get a route on its ownthat (periodically) gathers the respective messages. The intermediatetransformation t_(re) is defined ast_(re1):n_(i)⊕{n_(j)}→n_(fd)⊕n_(file)⊕{n_(j)}, with n_(i),n_(j) ∈ V_(P),which takes all matching enricher nodes n_(i) and the list of connectednodes {n_(j)} and translates them to a from-direct node n_(fd) that isfollowed by a file relation n_(file), referencing the connected nodes{n_(j)}. Additionally, all original edges e_(m) from the enricher n_(i)to the list of connected nodes {n_(j)} have to be removed:t_(er2):E_(P)→E_(P)\e_(m). The match condition for the remote enricheris the node type type(n_(i)), determined through the @enrich annotation:mc_(RE)=type(n_(i))==‘enrich’. After the intermediate translation, allproduced relations (nodes) that are linked to nodes in the main treecreate a join router (cf. transformations t_(jr1—3)) with a built-inaggregator that merges the facts, e.g., via union operation. In order tofind the complete path of nodes to extract, the leaving edges have to befollowed starting at the enricher node until a node that has multipleincoming nodes. Before the node with multiple incoming nodes, ato-direct node is inserted through t_(jr2) (dashed lines 752 and 754).The URI of the call to enricher node is set to the URI of the consumer,which can be added directly before the enricher node.

Message Channel Synthesis

The RG represents the foundation for the code synthesis of the messagechannels that include a combination of ILP constructs and APACHE CAMELpatterns and routes. The construction of the routes can be based on agraph traversal starting from the fact source nodes. The multicastt_(mu1,2) and join router t_(jr1—3) transformations construct a RG withdeg⁻(n)==1, with n ∈ V_(R). Hence, the ILP constructs can be synthesizedone after the other based on their types and the ILP properties, whichwere preserved during the transformations and optimizations.

FIG. 9 is an example route graph 900 in EIP-icon notation correspondingto the LDG 400 of FIG. 4 and the LiLa program in Listing 300 of FIG. 3for the soccer player event scenario. The RG 900 shows the synthesizedAPACHE CAMEL routes in the EIP-icon notation. Compared to the examplediagram 200 in FIG. 2, the content-based router 220 in FIG. 2 isreplaced by a multicast 920, and two message filters 922 and 924 areadded before the outbound message endpoints, while preserving the samesemantics and allowing for parallel message processing.

Message Endpoints

The fact source and routing goal nodes can be transformed to componentsin APACHE CAMEL, passing the configurations that are stored in the nodeproperties. A detected (not @from annotated) fact source gets anadditional numOfMsgsToAgg property, which remembers the entering messagecount of a join router (e.g., a structural/channel n:1 element), and asubsequently added, corresponding aggregator ILP (e.g., a messagecombining m:1 element) with completionSize=numOfMsgsToAgg. The locationproperty defines the component's endpoint configuration and the formatleads to the generation of an ILP format converter (e.g., JSON, CSV toDATALOG) that is configured using the meta-facts supplied in theannotation body, conducting an additional projection. In someimplementations, if the format is set to DATALOG, no format conversionis needed. The routing goals are configured similarly. A message filterILP is added that discards empty messages. The format converter (e.g.,DATALOG to JSON/CSV) can be added and configured through the meta-factsproperty. Finally, a CAMEL producer component is added to the route andconfigured.

Complex Routing Patterns

For the aggregator, additional renamingRules properties and renamingmessage translators are generated, containing a DATALOG rule that adds-aggregate suffixes to every DATALOG predicate used in the head of aquery (for name differentiation). Similarly, for the splitter, -splitsuffixes are generated that allow additional message translators torename the predicates. In some instances, this is necessary in order tobuild the dependency graph.

The inherent multicast nodes are configured through a recipient listproperty, containing the target node identifiers, which allows for atranslation to the CAMEL multicast (no ILP defined).

Message Translation Patterns

The content filter and message translator nodes can be generated to theILP content filter, which is based on a CAMEL processor and configuredaccordingly. The node of the inherent content enricher, which can bespecified by writing facts into a LiLa program, stores the facts asproperties. The generated ILP (again based on a CAMEL processor) addsthe facts to every incoming message. The explicit file enricher patternis configured similarly to a fact source; however, the configurationspecifies a fileName property, used to configure the CAMEL component.Again, ILP format converters are added and configured by the meta-factsproperty.

FIG. 10 is a listing of an example extended LiLa program 1000 of thesoccer game event integration scenario of FIG. 2 according to animplementation. In LiLa, program 1000 extends the calculation of theplayer's position (see posAtShotOnGoal), while shooting on goal, and tosample the player positions on a minute basis by using a recursive rule(see pPosPerMinute). The extended LiLa program 1000 “tweets” thecalculated positions and stores them with the “players at ball” to afile, and stores the positions per minute to a database.

FIG. 11 is an example (extended) LiLa dependency graph (LDG) 1100corresponding to the extended LiLa program 1000 of FIG. 10; FIG. 12 isan example route graph (RG) 1200 generated based on the LDG 1100 shownin FIG. 11. For example, as the node posAtShotOnGoal 1102 in FIG. 11 hasmultiple incoming arcs 1112 and 1114, a join router pattern is detectedand join router pattern 1202 is generated in FIG. 12. Similarly,multicast patterns 1212 and 1214 are generated after thefrom(file:playerPosition,json) node 1204 and gByP node 1206 based on thedetected multicast patterns in FIG. 11.

FIG. 13 is a flowchart of an example method 1300 for data-centricintegration modeling according to an implementation. For clarity ofpresentation, the description that follows generally describes method1300 in the context of FIGS. 1-12. However, it will be understood thatthe method 1300 may be performed, for example, by any other suitablesystem, environment, software, and hardware, or a combination ofsystems, environments, software, and hardware as appropriate. Forexample, the server 104 and/or its components can be used to execute themethod 1300.

At 1310, a logic integration program is defined. The logic integrationprogram can include multiple logic integration patterns that are definedusing a data-centric logic integration language (LiLa), for example, fordeclarative integration programming (namely, describing “what” isexpected rather than “how” it shall be done). The logic integrationprogram can be defined by representing the logic integration patternsaccording to the LiLa semantics. Example logic integration programs areshown in Listings 3 and 10 in FIGS. 3 and 10, respectively.

In some implementations, defining a logic integration program caninclude analyzing integration logic (1320) and adding integrationartifacts (1330). In some implementations, integration logic arerepresented by a logical model graph. In some implementations, analyzingintegration logic can include, identifying integration operations suchas, routing condition, mapping program, or other operations (1322);attaching data and formats required by single operations (1324), forexample, according to the LiLa semantics; and analyzing data and formatsdown to the field level for each integration operation (1326). A fieldsis part of a structure of a database table, described by type and value.The dependencies of operations in the logical model graph on thesefields can be analyzed and optimizations can be conducted, for example,by early filtering of unused fields, dedicated partitioning/shipment offields to specific operations, etc. In some implementations, addingadditional integration artifacts can include adding endpoint-specificextensions (1332) and adding routing-specific extensions (1334), forexample, according to the example techniques described with reference toTables 2 and 3. In some implementations, a pattern matching approach canbe used to detect integration-related artifacts and patterns on thelogical model graph. An annotation language (e.g., extension of standardlogic programming languages) can be used to allow defining integrationartifacts like endpoint configurations, complex routing, etc. From 1310,method 1300 proceeds to 1340.

At 1340, the logic integration program is received, for example, by anintegration system 100. From 1340, method 1300 proceeds to 1350.

At 1350, a logical model graph based on the logic integration program isbuilt. The logical model graph can include the LiLa dependency graph(LDG) (e.g., the example LDGs 400 and 1100). The logical model graph canbe runtime-independent (namely, it does not rely on any specificintegration runtime system). Example techniques for generating thelogical model graph are described above with respect to FIGS. 4 and 11.In some implementations, generating the logical model graph can includeconnecting nodes (including extensions, operators, etc.) with requireddata nodes (e.g., nodes in the logical model graph that represent theoperations on the data, nodes that represent the data, etc.) (1352), andderiving inherent integration operations (1354). For example, contentand message filters, multicast, and internal enricher can be derivedbased on the data flow and message format analysis and best practices(e.g., the map-reduce-like scatter/gather processing). From 1350, method1300 proceeds to 1360.

At 1360, the logical model graph is converted into a physical modelgraph. The physical model graph can be runtime-specific (e.g., dependenton a particular integration runtime system (e.g., the integration systemruntime 182 in FIG. 1B). For example, the physical model graph caninclude the example route graphs (RGs) 500 and 1200 that are designedfor APACHE CAMEL runtime. Additional or different integration runtimesystems can be used. In some implementations, converting the logicalmodel graph into the physical model graph can include detecting patternsof the logical model graph (1362); optimizing the logical model graph(1364); and synthesizing one or more message channels based on thedetected patterns (1366), for example, according to the exampletechniques described with reference to FIGS. 4-12. The physical modelgraph (e.g., the route graph) can be synthesized by performing arule-based transformation on the logical model graph (e.g., the LiLadependency graph) and then be mapped into implementation-specificmessaging channels. The logical model graph itself can be an abstractrepresentation of a messaging channel. From 1360, method 1300 proceedsto 1370. Example patterns can include one or more join router patterns,remote enricher patterns, and multicast patterns described withreference to FIGS. 6A-B, 7A-B, and 8A-B, respectively.

At 1370, logic integration runtime codes (or patterns, programs, etc.)executable by the integration system can be generated based on thephysical model graph. From 1370, method 1300 proceeds to 1380.

At 1380, the generated logic integration runtime codes can be packagedand deployed to integration runtime system, such as, APACHE CAMEL orother runtime system. After 1380, method 1300 stops.

Implementations of the subject matter and the functional operationsdescribed in this specification can be implemented in digital electroniccircuitry, in tangibly embodied computer software or firmware, incomputer hardware, including the structures disclosed in thisspecification and their structural equivalents, or in combinations ofone or more of them. Implementations of the subject matter described inthis specification can be implemented as one or more computer programs,i.e., one or more modules of computer program instructions encoded on atangible, non-transitory computer storage medium for execution by, or tocontrol the operation of, data processing apparatus. Alternatively or inaddition, the program instructions can be encoded on an artificiallygenerated propagated signal, e.g., a machine-generated electrical,optical, or electromagnetic signal that is generated to encodeinformation for transmission to suitable receiver apparatus forexecution by a data processing apparatus. The computer storage mediumcan be a machine-readable storage device, a machine-readable storagesubstrate, a random or serial access memory device, or a combination ofone or more of them.

The terms “data processing apparatus,” “computer,” or “electroniccomputer device” (or equivalent as understood by one of ordinary skillin the art) refer to data processing hardware and encompass all kinds ofapparatus, devices, and machines for processing data, including by wayof example, a programmable processor, a computer, or multiple processorsor computers. The apparatus can also be or further include specialpurpose logic circuitry, e.g., a central processing unit (CPU), an FPGA(field programmable gate array), or an ASIC (application-specificintegrated circuit). In some implementations, the data processingapparatus and/or special purpose logic circuitry may be hardware-basedand/or software-based. The apparatus can optionally include code thatcreates an execution environment for computer programs, e.g., code thatconstitutes processor firmware, a protocol stack, a database managementsystem, an operating system, or a combination of one or more of them.The present disclosure contemplates the use of data processingapparatuses with or without conventional operating systems, for exampleLINUX, UNIX, WINDOWS, MAC OS, ANDROID, IOS, or any other suitableconventional operating system.

A computer program, which may also be referred to or described as aprogram, software, a software application, a module, a software module,a script, or code, can be written in any form of programming language,including compiled or interpreted languages, or declarative orprocedural languages, and it can be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitsuitable for use in a computing environment. A computer program may, butneed not, correspond to a file in a file system. A program can be storedin a portion of a file that holds other programs or data, e.g., one ormore scripts stored in a markup language document, in a single filededicated to the program in question, or in multiple coordinated files,e.g., files that store one or more modules, sub-programs, or portions ofcode. A computer program can be deployed to be executed on one computeror on multiple computers that are located at one site or distributedacross multiple sites and interconnected by a communication network.While portions of the programs illustrated in the various figures areshown as individual modules that implement the various features andfunctionality through various objects, methods, or other processes, theprograms may instead include a number of sub-modules, third-partyservices, components, libraries, and such, as appropriate. Conversely,the features and functionality of various components can be combinedinto single components as appropriate.

The processes and logic flows described in this specification can beperformed by one or more programmable computers executing one or morecomputer programs to perform functions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., a CPU, an FPGA, or an ASIC.

Computers suitable for the execution of a computer program can be basedon general or special purpose microprocessors, both, or any other kindof CPU. Generally, a CPU will receive instructions and data from aread-only memory (ROM) or a random access memory (RAM) or both. Theessential elements of a computer are a CPU for performing or executinginstructions and one or more memory devices for storing instructions anddata. Generally, a computer will also include, or be operatively coupledto receive data from or transfer data to, or both, one or more massstorage devices for storing data, e.g., magnetic disks, magneto opticaldisks, or optical disks. However, a computer need not have such devices.Moreover, a computer can be embedded in another device, e.g., a mobiletelephone, a personal digital assistant (PDA), a mobile audio or videoplayer, a game console, a global positioning system (GPS) receiver, or aportable storage device, e.g., a universal serial bus (USB) flash drive,to name just a few.

Computer-readable media (transitory or non-transitory, as appropriate)suitable for storing computer program instructions and data include allforms of non-volatile memory, media, and memory devices, including byway of example, semiconductor memory devices, e.g., erasableprogrammable read-only memory (EPROM), electrically erasableprogrammable read-only memory (EEPROM), and flash memory devices;magnetic disks, e.g., internal hard disks or removable disks; magnetooptical disks; and CD ROM, DVD+/−R, DVD-RAM, and DVD-ROM disks. Thememory may store various objects or data, including caches, classes,frameworks, applications, backup data, jobs, web pages, web pagetemplates, database tables, repositories storing business and/or dynamicinformation, and any other appropriate information including anyparameters, variables, algorithms, instructions, rules, constraints, orreferences thereto. Additionally, the memory may include any otherappropriate data, such as logs, policies, security or access data,reporting files, as well as others. The processor and the memory can besupplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, implementations of the subjectmatter described in this specification can be implemented on a computerhaving a display device, e.g., a CRT (cathode ray tube), LCD (liquidcrystal display), LED (Light Emitting Diode), or plasma monitor, fordisplaying information to the user, and a keyboard and a pointingdevice, e.g., a mouse, trackball, or trackpad, by which the user canprovide input to the computer. Input may also be provided to thecomputer using a touchscreen, such as a tablet computer surface withpressure sensitivity, a multi-touch screen using capacitive or electricsensing, or other type of touchscreen. Other kinds of devices can beused to provide for interaction with a user as well; for example,feedback provided to the user can be any form of sensory feedback, e.g.,visual feedback, auditory feedback, or tactile feedback; and input fromthe user can be received in any form, including acoustic, speech, ortactile input. In addition, a computer can interact with a user bysending documents to and receiving documents from a device that is usedby the user; for example, by sending web pages to a web browser on auser's client device in response to requests received from the webbrowser.

The term “graphical user interface,” or “GUI,” may be used in thesingular or the plural to describe one or more graphical user interfacesand each of the displays of a particular graphical user interface.Therefore, a GUI may represent any graphical user interface, includingbut not limited to, a web browser, a touch screen, or a command lineinterface (CLI) that processes information and efficiently presents theinformation results to the user. In general, a GUI may include aplurality of user interface (UI) elements, some or all associated with aweb browser, such as interactive fields, pull-down lists, and buttonsoperable by the business suite user. These and other UI elements may berelated to or represent the functions of the web browser.

Implementations of the subject matter described in this specificationcan be implemented in a computing system that includes a back-endcomponent, e.g., as a data server, or that includes a middlewarecomponent, e.g., an application server, or that includes a front-endcomponent, e.g., a client computer having a graphical user interface ora web browser through which a user can interact with an implementationof the subject matter described in this specification, or anycombination of one or more such back-end, middleware, or front-endcomponents. The components of the system can be interconnected by anyform or medium of wireline and/or wireless digital data communication,e.g., a communication network. Examples of communication networksinclude a local area network (LAN), a radio access network (RAN), ametropolitan area network (MAN), a wide area network (WAN), WorldwideInteroperability for Microwave Access (WIMAX), a wireless local areanetwork (WLAN) using, for example, 802.11 a/b/g/n and/or 802.20, all ora portion of the Internet, and/or any other communication system orsystems at one or more locations. The network may communicate with, forexample, Internet Protocol (IP) packets, Frame Relay frames,Asynchronous Transfer Mode (ATM) cells, voice, video, data, and/or othersuitable information between network addresses.

The computing system can include clients and servers. A client andserver are generally remote from each other and typically interactthrough a communication network. The relationship of client and serverarises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other.

In some implementations, any or all of the components of the computingsystem, both hardware and/or software, may interface with each otherand/or the interface using an application programming interface (API)and/or a service layer. The API may include specifications for routines,data structures, and object classes. The API may be either computerlanguage-independent or -dependent and refer to a complete interface, asingle function, or even a set of APIs. The service layer providessoftware services to the computing system. The functionality of thevarious components of the computing system may be accessible for allservice consumers using this service layer. Software services providereusable, defined business functionalities through a defined interface.For example, the interface may be software written in JAVA, C++, orother suitable language providing data in Extensible Markup Language(XML) format or other suitable format. The API and/or service layer maybe an integral and/or a stand-alone component in relation to othercomponents of the computing system. Moreover, any or all parts of theservice layer may be implemented as child or sub-modules of anothersoftware module, enterprise application, or hardware module withoutdeparting from the scope of this disclosure.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinvention or on the scope of what may be claimed, but rather asdescriptions of features that may be specific to particularimplementations of particular inventions. Certain features that aredescribed in this specification in the context of separateimplementations can also be implemented in combination in a singleimplementation. Conversely, various features that are described in thecontext of a single implementation can also be implemented in multipleimplementations separately or in any suitable sub-combination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to asub-combination or variation of a sub-combination.

Particular implementations of the subject matter have been described.Other implementations, alterations, and permutations of the describedimplementations are within the scope of the following claims as will beapparent to those skilled in the art. While operations are depicted inthe drawings or claims in a particular order, this should not beunderstood as requiring that such operations be performed in theparticular order shown or in sequential order, or that all illustratedoperations be performed (some operations may be considered optional), toachieve desirable results. In certain circumstances, multitasking andparallel processing may be advantageous.

Moreover, the separation and/or integration of various system modulesand components in the implementations described above should not beunderstood as requiring such separation and/or integration in allimplementations, and it should be understood that the described programcomponents and systems can generally be integrated together in a singlesoftware product or packaged into multiple software products.

Accordingly, the above description of example implementations does notdefine or constrain this disclosure. Other changes, substitutions, andalterations are also possible without departing from the spirit andscope of this disclosure.

What is claimed:
 1. A computer-implemented method comprising: receiving,by operation of an integration system, a logic integration programcomprising a plurality of logic integration patterns that are defined ina data-centric logic integration language; generating a logical modelgraph based on the logic integration program, the logical model graphbeing runtime-independent; defining the logic integration program byanalyzing integration logic represented by the logical model graph andadding integration artifacts, wherein integration artifacts comprise atleast one of endpoint-specific extensions or routing-specificextensions; bi-directionally converting the logical model graph into aphysical model graph, the physical model graph being runtime-specificby: detecting patterns on the logical model graph; performing arule-based transformation on the logical model graph; and mapping thetransformed logical model graph into implementation-specific messagingchannels in accordance with the integration artifacts and generatinglogic integration runtime codes executable by the integration systembased on the physical model graph.
 2. The method of claim 1, wherein thelogical model graph comprises one or more annotations defined by thedata-centric logic integration language as one or more nodes of thelogical model graph.
 3. The method of claim 1, wherein the logical modelgraph comprises no cycles.
 4. The method of claim 1, further comprisingoptimizing the logical model graph.
 5. The method of claim 1, whereinthe routing-specific extension comprises at least one of: an aggregator;a splitter; or a content enricher.
 6. The method of claim 1, wherein theendpoint-specific extension comprises at least one of: a content filter;a message translator; or a local content enricher.
 7. A non-transitory,computer-readable medium storing computer-readable instructionsexecutable by a computer and configured to: receive a logic integrationprogram comprising a plurality of logic integration patterns that aredefined in a data-centric logic integration language; generate a logicalmodel graph based on the logic integration program, the logical modelgraph being runtime-independent; define the logic integration program byanalyzing integration logic represented by the logical model graph andadding integration artifacts, wherein integration artifacts comprise atleast one of endpoint-specific extensions or routing-specificextensions; bi-directionally convert the logical model graph into aphysical model graph, the physical model graph being runtime-specificby: detecting patterns on the logical model graph; performing arule-based transformation on the logical model graph; and mapping thetransformed logical model graph into implementation-specific messagingchannels in accordance with the integration artifacts; and generatelogic integration runtime codes executable by an integration systembased on the physical model graph.
 8. The medium of claim 7, wherein thelogical model graph comprises one or more annotations defined by thedata-centric logic integration language as one or more nodes of thelogical model graph.
 9. The medium of claim 7, wherein the logical modelgraph comprises no cycles.
 10. The medium of claim 7, the instructionsfurther executable by the computer and configured to optimize thelogical model graph.
 11. A system, comprising: a memory; at least onehardware processor interoperably coupled with the memory and configuredto: receive a logic integration program comprising a plurality of logicintegration patterns that are defined in a data-centric logicintegration language; generate a logical model graph based on the logicintegration program, the logical model graph being runtime-independent;define the logic integration program by analyzing integration logicrepresented by the logical model graph and adding integration artifacts,wherein integration artifacts comprise at least one of endpoint-specificextensions or routing-specific extensions; bi-directionally convert thelogical model graph into a physical model graph, the physical modelgraph being runtime-specific by: detecting patterns on the logical modelgraph; performing a rule-based transformation on the logical modelgraph; and mapping the transformed logical model graph intoimplementation-specific messaging channels in accordance with theintegration artifacts; and generate logic integration runtime codesexecutable by an integration system based on the physical model graph.12. The system of claim 11, wherein the logical model graph comprisesone or more annotations defined by the data-centric logic integrationlanguage as one or more nodes of the logical model graph.
 13. The systemof claim 11, wherein the logical model graph comprises no cycles. 14.The system of claim 11, wherein converting the logical model graph intothe physical model graph comprises: optimizing the logical model graph.